Method for producing propeller-blade patterns.



W. R. BOUTWELL. METHOD FOR PRODUCING PROPELLER BLADE PATTERNS.

APPLICATION FILED MAY 27, 1912.

Patented May 27; 1913.

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3 n-wutoz mam i2 Bauwc/Z W. R. BOUTWELL. METHOD FOR PRODUCING PROPELLERBLADE PATTERNS.

APPLICATION FILED MAY 27, 1912. R

Patented May 27, 1913.

3 SHEETS-SHEET 2.

W. R. BOUTWELL. METHOD FOR PRODUCING PROPELLER BLADE PATTERNS.APPLICATION FILED MAY 27, 1912.

1,062,762. Patented May 27, 1913.

3 SHEETS-SHEET 3.

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UNITED STATES R. BOUTWELL,

0F NORFOLK, VIRGINIA.

METHOD FOR, PRODUCING PROPELLER-IBLADE PATTEIIS.

Specification of Letters Patent.

Patented May2'7, 1913.

Application filed May 27, 1912. Serial 110. 700,088.

To all 'wlwmit may concern:

Be itiknown that I, WILLIAM R. BoU'r- WELL, a citizen of the UnitedStates, residing at Norfolk, in the county of Norfolk and State ofVirginia, have invented new and useful Improvements in Methods forProducing Propeller-Blade Patterns, of which the following is aspecification.

This invention relates to an improved method for producing patterns, andhas particular reference to a method for making patterns from which maybe cast peculiarly ormed blades of propellers for water and air craftwhereby, under set conditions, the highest possible speed of the craftmay be obtained for the least expenditure of power, and from. which maybe cast propeller blades of various forms ada table to various uses asmay be found desira 1e.

The invention has 'for an object, to provide a simple method of forming,not only propeller blades of various shapes and sizes,

ut also all manner of articles-and parts of devices which, generally,have the same characteristics as these peculiarly formed propellerblades. v

This invention designs to gzproduce patterns from which may be cast apropeller blade having grooved or dishdfaces varying in cross-sectionalform, as shown in the accompanyin drawings and specifically referred toin t e following detail description.

The groove in the propeller blade is areshaped and formed on a circle ofthe same diameter throughout its width and concentric to the propellerin its assembled form. The circle of the inner edge of the groove of thepro eller'blade is concentric with the circle of t e outer edge of thegroove. It is designed to produce a number of these peculiarly formedpropeller blades which have a uniform dept of groove of the characterspecified, and mount these blades on a common hub. The pro eller bladesare adapted to be so arrange on the hub that the grooved faces areangled more or less obliquely to the axis of rotation to formdriving-faces, the tops of the grooves being positioned a distance fromthe center of the hub e ual to the radius of the circle of the top edgesof the grooves.

' riefly stated, the improved method is carried out in the .followmgmanner: First, a block of suitable material is placed upon a lathe, orth'e' iike, and turned'down to the oove, or grooves, so as to vcurvilinear form. Third, the blank is now 7 cut into segments, each ofwhich is of a size substantially the size of the blade or article whichis to be formed. The cuts dissecting the blank extend through the groovetransversely or obliquely, whereby the groove extends transverselyacross the face of the segment. And lastly, the segments are each workeddown to the desired shape or contour of the propeller blade or othervarticle desired. I

Various other minor objects will appear from the detail description ofthis improved method in conjunction with the accompanying drawingsreferred to in such description.

In the drawings, F' re 1 is a perspective view of a disk blank om whicha nu ber of patterns are formed; Fig. 2 is a front elevation of theblank having the concentric groove formed therein; Fig. 3 is a centralsectional view taken on the line 3-3 of Fig. 2 disclosing thecomplementary formation of the rear side of the blank; Fig. i is a frontelevation of the blank cut into segments, and showing in dotted linesthe contour of pro eller blades adapted to be .worked out oi thesegments; Fig. 5 is a face view of a finished propeller blade; Fig. 6

is a front elevation of the grooved blank cut into segments differingfrom Fig. 4, showing in dotted lines the contours of another form ofpropeller blade which may be worked out of the segments; Fig. 7 is aface view of a propeller blade of a further configuration; Fig. 8 is acentral cross section view of theblank having two concentric groovesformed in the front face thereof, and showing complementary grooves inthe rear face thereof; Fig. 9 is a front elevation of the complete blankof the form disclosed in Fig. 8; Figs. 10 to 13 inclusive illustrate insec tion some of the various grooves which ma be formed in the blankdisk from whic correspondingly shaped patterns are to be out.

In carrying out this invention a disk blanklO, such as disclosed in Fig.1 of the drawings, is placed .upon a lathe, or other 0 thickness of theoriginal blank.

suitable turning machine, and is formed with a groove 11 concentric tothe center of curvature of the disk and having its inner marginal edgespaced considerably from the central portion of the disk. The blank disk10 may be suitably turned down from any shape in which the material isfound prior to working the same in accordance with the steps of thisimproved method. The groove 11 is arc-shaped, as'may be seen toadvantage in Fig. 3, and the central portion 12' of the disk is leftuncut so that it has the The disk thus treated is further turned and acomplementary groove 13 is cut into the opposite or rear face of theblank to form a convex rear face, and to give the blank the desiredthickness at the grooved port-ion. Thus formed, the disk or blankassumes the contour disclosed in section in Fig. 3. The next step in themethod is in cutting the blank into a number of segments or parts ofsufficient size to contain the desired pattern.

In Fig. 1 of the drawings the cuts 14 are disclosed as being inparallelism and in the direction of cords of the circular contour of thedisk, and dividing the disk into three parts, 15, 16 and 17'. The mainor intermediate part 15 of the disk has portions extending fromdiametrically opposite points about the central portion 12. The parts 16and 17 are removed from the central part 15, and the part 15 is workedin any suitable manner to cut away the excess material about theproposed propeller blade whereby a blade of the configuration disclosedin Fig. 5 is produced. The central portion 12 is left thicker than thegrooved portion of the disk so that a stem 18 may be formed upon theinner end of the blade and extend centrally therefrom for the purpose ofsupportting the blade in true circular relation to similar bladesmounted upon a common hub.

In Fig. 6 of the drawings is disclosed another manner of dividing thedisk blank. In Fig. 6 the cuts 14: extend at right angles to each otherand divide the disk into four equal parts or segments 15. This cuttingof the disk is resorted to when it is desired to form a propeller bladeof substantial width at its intermediate portion, and where the innermarginal edge of the groove is of reduced length. As will be observedfrom Fig. 6, the cutting of the disk through its central portion 12provides ample space for propeller blades of considerable size, andstems upon the blades for supporting the blades upon the hub. Further,it will be noted that in cutting the disk as disclosed in Fig. 6 fourblades may be produced from one disk, whereas in the cutting of theblade as disclosed in Fig. 4, but two blades can be produced.

Fig. 7 of the drawings discloses a further or modified form of bladewhich may be conveniently made from the disk when cut as in Fig. 6. Thispropeller blade 19, disclosed in Fig. 7, is of substantial pear-shapeand may be readily formed from a blank or pattern produced from the diskas cut in Fig. 6. It will, of course, be understood that the blanks maybe cut in any desired manner to produce a number of segments or parts,each one of which contains a propeller blade,

'or other device which is to be produced from the blank. It will also beunderstood that in the disk 10 may be formed not only one concentricgroove, but two or more of the same, so as to provide a number ofarc-shaped faces constituting working faces for the propeller formedfrom these blades.

Figs. 8 and 9 illustrate the disk having two concentric grooves 11 inthe working face, and the complementary grooves 13 in its opposite orrear face, giving to the pattern the true shape and thickness of thepropeller blade to be cast.

In Fig. 1O of the drawings the disk blank 10 is disclosed as having asingle concentric groove 11 in its working face extending in width fromthe edge of the central thick portion to the outer edge of the blank,and the complementary groove 18 in the rear face of the blank 10 isformed eccentric to the groove 11 forming a body for the pattern whichgradually tapers in thickness from the central portion 12 to the outeredge of the blank.

Fig. 11 shows the complementary grooves 11 and 13 formed in the blank 10so as to provide a flat portion 10 immediately adjacent the thickcentral portion 12, and in a plane at right angles to the axis of theblank 10. This formation of the grooves provides a concentric taperingbody about the fiat portion 10.

A tapering body which inclines forwardly and uniformly from the centralthick portion 12 is shown' in section in Fig. 12, wherein the groove 11in the working face is formed with its deepest portion immediately atthe central portion 12 of the blank 10, and wherein the complementarygroove 13 in the rear face of the blank is formed not only eccentric tothe working face but also has its deepest portion at the outer edge ofthe blank.

Another formation of groove is shown in Fig. 13 wherein the grooves 11and 13"are not formed in the arc of a circle, but are formed to provideoppositely inclined flat faces. In the working face of the blank theopposite inclined faces converge to a point intermediate of the thickcentral portion 12, and the outer edge of the blank, which intermediatepoint is the deepest portion of the groove so that the patterns willpresent a concave working face and a convex rear face as in the otherforms above described. In this form, shown in Fig. 13, the body 10 isintegral with the pattern.

also tapered by forming the complementary grooves 11* and 13 eccentricto one another.

It is, of-course, understood that any other adaptable form may be giventhe pattern by peculiarly forming the grooves 11 and 13 in the oppositesides of the blank 10, and in forming any desired number of grooves inthe blank. 0

What I claim is:

1. That method of forming propeller blade patterns which consists informing a circular groovein a disk of material, the groove being formedconcentric to the disk leaving the central portion of the disk thickerthan the grooved portion, cutting the disk to provide a number ofindependent parts, and workingdown the arts to produce a pattern of thedesired width, the thickened central part being Worked clown to providea stem for the propeller blade pattern.

2. The method of forming a propeller blade pattern which consists inconcentrically grooving the side of a disk blank and leaving the centralportion thereof thicker than the grooved portion of the blank, thencutting said blankto-provide apart havin a width substantially equal tothe width 0' the desired pattern, and finally turning down the sectionto produce'the propeller blade, the central thickened portion of theblank being turned down to provide a'stem 3. The method of formingpatterns for propeller blades which consists in first: forming aconcentric groove in a cylindrical blank leaving the central portion ofthe blank thicker than the grooved portion, second: cutting the blankthrough the groove to form a number of segments having transversegrooves therein, and third: working down the segments to providepatterns for the propeller blades from the grooved portions and stemsfor the blades from the thickened central portions.

4. That method of forming propeller blade patterns which consists incutting a concentric groove, or grooves, arcuate in cross-section in theface of a blank leaving a central thickened portion cutting the blankthrough the arcuate groove or grooves and the thickened portion toprovide a number of parts each having a thickened inner end, and workingdown each part to pro duce the blade patterns desired, the thickened.inner ends being worked down to produce stems for the parts.

5. Themethod of forming patterns for water and air craft propellerblades which consists in forming complementary grooves in the oppositesides of a disk blank and leaving a central thickened portion, cuttingthe disk blank through the grooves into a number of parts, and workingdown the desired patterns of the blade from the said parts and-workingthe stems for the blade patterns from the central thickened portion. 6.The method of formin patterns for water and air craft propel er bladesand other articles having like characteristics which consists in formingcomplementary and concentric grooves in the opposite faces of a diskblank leaving a thickened central portion, cutting the blank through thegrooves and the central thickened portion into a number of parts, andworking down the patterns desired from the grooved parts and stems forthe patterns from the thickened parts.

Intestimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

WILLIAM R. BOUTWELL. Witnesses:

R. C. HENLEY, I ELMER WING.

